The present disclosure describes an electric air filtration device. More specifically, this disclosure describes a device that applies an electric field to charge particles to be removed from a gaseous stream during filtration.
Particulate matter removal from a gaseous stream using a fibrous mat has been a long-established process. Particle accumulation increases the collection efficiency of mechanical fibrous filter but also increases the pressure drop (or resistance) across the filter. The continuous increase in pressure drop leads to filter clogging, which is typically demonstrated by an abrupt increase in pressure drop with loading.
Air filtration systems can utilize electronic or electrostatic technology to enhance the performance of the filtration medium. Electrical air filters can obtain a higher efficiency from a given mechanical filter because electricity is used to induce a polarization state in the fibers of a non-metallic filtration medium. The applied electric field also induces a polarization state in at least some of the particles within the air stream to be filtered. The electrostatic forces in the particles and the filter medium attract one another to bind the particles to the medium. These forces of electrostatic attraction can increase the filtration efficiency of a given filtration medium by several fold.
In a typical electrostatic precipitator, charged particles travel in a flow direction which is parallel to the charged collection plate. During precipitation, undesirable re-suspension of particles previously collected on the collection plate to the air stream occurs.
The present application describes techniques of filtering air using electrostatic charges.